package com.liuze.websocketdemo.webSocketServer;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;

import javax.websocket.*;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * @ClassName WebSocketServer
 * @Author 刘泽
 * @Mail liuze713@hotmail.com
 * @Date 2022/3/14 2:47 PM
 * @Version 1.0
 */
@ServerEndpoint("/imserver/{userId}")
@Component
@Slf4j
public class WebSocketServer {
    /**
     * 静态变量，用来记录当前在线连接数。应该把它设计成线程安全的。
     */
    private static int onlineCount = 0;
    /**
     * concurrent包的线程安全Set，用来存放每个客户端对应的MyWebSocket对象。
     */
    private static ConcurrentHashMap<String, WebSocketServer> webSocketMap = new ConcurrentHashMap<>();
    /**
     * 与某个客户端的连接会话，需要通过它来给客户端发送数据
     */
    private Session session;
    /**
     * 接收userId
     */
    private String userId = "";

    /**
     * 连接建立成功调用的方法
     */
    @OnOpen
    public void onOpen(Session session, @PathParam("userId") String userId) {
        this.session = session;
        this.userId = userId;
        if (webSocketMap.containsKey(userId)) {
            webSocketMap.remove(userId);
            webSocketMap.put(userId, this);
            //加入set中
        } else {
            webSocketMap.put(userId, this);
            //加入set中
            addOnlineCount();
            //在线数加1
        }

        log.info("用户连接:" + userId + ",当前在线人数为:" + getOnlineCount());

        try {
            sendMessage("连接成功");
            sendAllUserLogin();
        } catch (IOException e) {
            log.error("用户:" + userId + ",网络异常!!!!!!");
        }
    }

    private void sendAllUserLogin() {
        ArrayList<Map<String, String>> maps = new ArrayList<>();
        for (String key : webSocketMap.keySet()) {
            HashMap<String, String> stringStringHashMap = new HashMap<>();
            stringStringHashMap.put("value", key);
            stringStringHashMap.put("label", key);
            maps.add(stringStringHashMap);
        }
        HashMap<String, Object> stringObjectHashMap = new HashMap<>();
        stringObjectHashMap.put("userInfo", maps);
        for (String key : webSocketMap.keySet()) {
            try {
                webSocketMap.get(key).sendMessage(JSONObject.toJSONString(stringObjectHashMap));
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

    }

    /**
     * 连接关闭调用的方法
     */
    @OnClose
    public void onClose() {
        if (webSocketMap.containsKey(userId)) {
            webSocketMap.remove(userId);
            //从set中删除
            subOnlineCount();
        }
        sendAllUserLogin();
        log.info("用户退出:" + userId + ",当前在线人数为:" + getOnlineCount());
    }

    /**
     * 收到客户端消息后调用的方法
     *
     * @param message 客户端发送过来的消息
     */
    @OnMessage
    public void onMessage(String message, Session session) {
        log.info("用户消息:" + userId + ",报文:" + message);
        //可以群发消息
        //消息保存到数据库、redis
        if (StringUtils.hasLength(message)) {
            try {
                //解析发送的报文
                JSONObject jsonObject = JSON.parseObject(message);
                //追加发送人(防止串改)
                jsonObject.put("fromUserId", this.userId);
                String toUserId = jsonObject.getString("toUserId");
                String msg = jsonObject.getString("msg");
                //传送给对应toUserId用户的websocket
                if (StringUtils.hasLength(toUserId) && webSocketMap.containsKey(toUserId)) {
                    HashMap<Object, Object> hashMap = new HashMap<>(2);
                    hashMap.put("msg", msg);
                    hashMap.put("userId", userId);
                    webSocketMap.get(toUserId).sendMessage(JSON.toJSONString(hashMap));
                } else {
                    log.error("请求的userId:" + toUserId + "不在该服务器上");
                    //否则不在这个服务器上，发送到mysql或者redis
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * @param session
     * @param error
     */
    @OnError
    public void onError(Session session, Throwable error) {
        log.error("用户错误:" + this.userId + ",原因:" + error.getMessage());
        error.printStackTrace();
    }

    /**
     * 实现服务器主动推送
     */
    public void sendMessage(String message) throws IOException {
        this.session.getBasicRemote().sendText(message);
    }


    /**
     * 发送自定义消息
     */
    public static void sendInfo(String message, @PathParam("userId") String userId) throws IOException {
        log.info("发送消息到:" + userId + "，报文:" + message);
        if (StringUtils.hasLength(userId) && webSocketMap.containsKey(userId)) {
            webSocketMap.get(userId).sendMessage(message);
        } else {
            log.error("用户" + userId + ",不在线！");
        }
    }

    public static synchronized int getOnlineCount() {
        return onlineCount;
    }

    public static ConcurrentHashMap<String, WebSocketServer> getWebSocketMapS() {
        return webSocketMap;
    }

    public static synchronized void addOnlineCount() {
        WebSocketServer.onlineCount++;
    }

    public static synchronized void subOnlineCount() {
        WebSocketServer.onlineCount--;
    }
}
